Invert XYZ Euler Rotation Value
I set my selected object's rotation_mode to ZYXand entered the values as 

    selected_object.rotation_mode = 'ZYX'
    selected_object.rotation_euler[0] = rotX * -1
    selected_object.rotation_euler[1] = rotY * -1
    selected_object.rotation_euler[2] = rotZ * -1    


This rotated the object into the correct position.

Thanks Robert for the link :)